Long-term outcome following anterior cruciate ligament reconstruction: preliminary results of a 25-year prospective study

Abstract

Background: In 1993, Gillquist stated that the only effect of anterior cruciate ligament (ACL) reconstruction is to give the patient enough security to reach the goal of going back to strenuous sports and then ruining the knee. Very few long-term studies able to address this issue, exist. This prospective long-term study aims to investigate objective and subjective outcomes 25 years post-ACL reconstruction using either bone-patellar tendon-bone (B-PT-B) or semitendinosus/gracilis (STG) grafting. Methods: The first ten patients (7 males, 3 females, mean age 51 years, B-PT-B graft n=4, STG graft n=6) from a cohort of 62 patients operated on between 1996 and 1998 were assessed using the same measures as three previous time-frames. This cohort had followed comprehensive quadriceps-emphasised rehabilitation delivered by the same physiotherapist. Outcome measures included quadriceps and hamstring strength (Cybex 11), clinical and instrumented stability (KT1000), three agility tests (shuttle run, side-step, carioca), two hop tests (hop, triple hop), return to sport history, current sport involvement, and bilateral knee x-rays. Results: One patient ruptured their graft and contralateral patellar tendon; one patient tore their hamstring; one patient had two arthroscopies; and two patients ruptured their contralateral ACL, one of whom underwent bilateral total knee replacements (TKR). Mean quadriceps strength index (60°/sec) was 92%, and mean hamstring index was 90%. Mean KT1000 side-to-side difference (20 lbs) was 1mm. One patient had a positive pivot shift test and one a pivot glide. Excluding the patient with TKRs, nine patients performed the agility tests well. Mean hop indices were 94% for the hop and 96% for the triple hop (n=8). Nine patients had returned to competitive pivoting sport, three for nearly 20 years. Three patients continued to play competitive volleyball, cricket and soccer at Masters level. Six patients remained active in less vigorous activities (running, football coaching, golf, aerobics, gym). On x-ray, four patients had mild tibiofemoral osteoarthritis (TFOA), four had moderate TFOA and one had severe TFOA (Kellgren-Lawrence grading). Findings were similar for patellofemoral OA. No patient regretted having surgery. Discussion: The most important finding was the high level of strength, stability, function and sports participation found in this group, despite moderate-severe radiographic OA observed in half of the patients. Ongoing study of the full cohort will provide key information as to how clinicians can improve long-term results following ACL reconstruction. My co-authors and I acknowledge that we have no conflict of interest of relevance to submission of this abstract.